I am away from home at present, and, turning on the laptop, could not find any free wi fi access, but did find the BT wi fi-with-FON, so have paid, and it is working.
Avast went ballistic, and offered to protect me from a public network, but at a price, of course.
Without being paranoid, is there anything I should worry about, or any particular action I should take on this laptop (W7) whilst using the BT wi fi service?